Due to excellent optical properties, the acrylic resin is applied in various fields such as lens, automotive parts, lighting parts, electronic displays, and surface boards of a pachinko machine or the like. However, the acrylic resin of a related art has disadvantages of poor flexibility and poor impact resistance.
As a method for obtaining a molded article of acrylic resin with high flexibility and transparency, for example, in Patent Document 1 and 2, a method of obtaining a molded article by cast polymerization of a polymerizable composition containing di(meth)acrylate with a soft segment part and mono(meth)acrylate as a main component is suggested.
According to Patent Document 1, when di(meth)acrylate having a soft segment part with high molecular weight is used, excellent flexibility is obtained according to addition of a small amount relative to mono(meth)acrylate relative. However, the transparency is impaired due to increased haze. Furthermore, although a molded article with excellent flexibility is obtained in Patent Document 2 by mixing two kinds of di(meth)acrylate and one kind of mono(meth)acrylate, the glass transition temperature (TgDMS) of the molded article is as low as 40° C., exhibiting a lack of heat resistance.